Hotels, take heed. At the Black Hat Security Conference in Las Vegas last night, Mozilla software developer Cody Brocious showed us how to hack hotel key card readers. In 200 milliseconds using $20 of worth equipment, Brocious claims he can open any hotel door using the Onity system lock and contends there are ten million hotel rooms guarded by Onity's key card locks. That's a whole lot of burglary waiting to happen. Take a look at the slides on his website—what do you think hotels should do about it?